Highway (2)

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Present by:Cp 0310 (PARTH) Cp 0410 (DARSHAN)

Types Of PAVEMENT:-

FLEXIBLE PAVEMENT COMPONENTS

Surface Dressing

The friction course is the uppermost pavement layer and is designed to provide a skid resistant surface. The thickness of frictional course varies between 20mm 75mm. This comprises of bituminous and termed also as seal coat.

STRUCTURAL AND BASE COURSE

The structural course is designed to distribute the traffic loadings to the base course. The thickness of this course varies between 50mm 150mm. It may be composed of crushed stone, crushed slag, and other untreated or stabilized materials.

SUB-BASE COURSE

The sub-base layer is often the main load-bearing layer of a pavement. It is designed to evenly spread the load of the paving, and any traffic thereon, to the sub-grade below. Two different types of material are considered here Unbound Granular Material

Cement Bound Material The two most common binders are Bitumen (tar) Cement

Stabilized Sub-grade

This is a structural layer that is approx.12 (300 mm) thick. Sub-grades are commonly compacted before the construction of a pavement, and are sometimes stabilized by the addition of asphalt, soil, cement, Portland cement or lime. It is the foundation of the pavement structure. Preparation of its construction usually involves digging, in order to remove surface vegetation, topsoil and other unwanted material, and to create space for the upper layer of the pavement which is known as sub-grade formation. The load-bearing strength of sub-grade is measured by California Bearing Ratio (CBR) test.

Various Coats:

Seal Coat: Seal coat is a thin surface treatment used towater-proof the surface and to provide skid resistance.

Tack Coat: Tack coat is a very light application of asphalt,usually asphalt emulsion diluted with water. It provides proper bonding between two layer of binder course and must be thin, uniformly cover the entire surface, and set very fast.

Prime Coat: Prime coat is an application of low viscouscutback bitumen to an absorbent surface like granular bases on which binder layer is placed. It provides bonding between two layers. Unlike tack coat, prime coat penetrates into the layer below, plugs the voids, and forms a water tight surface.

FLEXIBLE PAVEMENT

Sub-grade: It is the normal soil on which the pavement rest and to which theentire load of the structure as well as that of traffic playing on the surface above is ultimately transferred.

Sub-base course: It is placed immediately above the sub-grade soil and iscomposed of hard well burnt clinker, natural gravel or any other suitable material.

Base course: It forms the structure proper of flexible composed of broken stonecemented together by materials which allow some degree of flexibility.

Surface course: It consist of a mixture of bituminous material and aggregateand forms the actual wearing coat.

Tests conducted

Tests for Bitumen Penetration Test Ductility Test Viscosity Test Softening Point Test Flash and Fire Point Test Spot Test Loss on Heating Test

Tests for sub grade

Tests for Aggregate Crushing Test Shape Test Abrasion Test Impact Test Soundness Test Shape Test Specific Gravity & Water Absorption Test Bitumen Adhesion Test

Penetration test Shear test Bearing test

UNBOUND / BOUND MATERIALS

Unbound materials are those aggregates which are loose and do not adhere to their neighbor but rely on the natural interlocking of adjacent particles. An unbound sub-base material can be loosened and removed quite easily. Bound materials are those which do bond with their neighboring particles by means of a "binder". Bound materials 'set' and are consequently more difficult to loosen and remove.

RIGID PAVEMENT

Materials for C.C Road:

Cement Content Coarse Aggregates

Maximum Cement: 425 kg/m3 Minimum Cement : 350 kg/m3

AIV: shall be < 30% for wearing surfaces LA abrasion value = 10 MPa

Types of SEALANTHot poured elastic type Hot poured rubberized asphalt(thermoplastic) Cold applied thermosetting type Performed compression seals

Ministry of Road Transport & Highways Standard Specifications for Road and Bridge Works - 4th Revision-2001

300 Earthwork, Erosion control and Drainage301 Excavation for roadway and drains 302 Blasting operations 303 presplit ting rock excavation slopes 304 Excavation for structures 305 Embankment construction 306 Soil erosion and sedimentation control 307 Turfing with sods 308 Seeding and mulching 309 Surface/ sub surface drains 310 Preparation and surface treatment of formation 311 works to be kept free of water 312 water course at culverts 313 Construction of rockfill embankment

400 Sub-bases, Bases (non bituminous) and Shoulders401 Granular Sub Base 402 Lime treated soil for improved sub grade/ sub base 403 Cement treated sub-base/ base 404 Water Bound macadam sub-base/ base 405 Crushed cement Concrete sub-base/ base 406 Wet Mix Macadam sub-base/ base 407 Shoulders, Island and Median 408 Cement concrete kerbs and kerb with channel 409 Footpaths and Seperators 410 Crusher-run Macadam base

500 Bases and Surface courses (Bituminous)501 General requirements for Bituminous pavement layers. Annexure A to 501: Protection of the Environment. 502 Prime coat over Granular Base 503 Tack coat 504 Bituminous Macadam 505 Bituminous Penetration Macadam 506 Built-up spray grout 507 Dense graded bituminous Macadam 508 Semi-Dense Bituminous concrete 509 Bituminous concrete 510 Surface Dressing 511 Open-Graded premix surfacing

500 Bases and Surface courses (Bituminous) continued512 Close-Graded premix surfacing/ Mixed seal surfacing 513 Seal coat 514 Supply of stone Aggregates for pavement courses 515 Mastic Asphalt 516 Slurry Seal 517 Recycling of Bituminous pavement 518 Fog Spray 519 Bituminous Cold Mix (Including Gravel Emulsion) 520 Sand Asphalt Base Course 522 Crack Prevention Courses

Other Important Sections600 Concrete Pavement 700 Geosynthetics 800 Traffic signs, markings & other road appurtenances 900 Quality control for road works 1000 Materials for structures 1100 Pile foundations 1200 Well foundations 1700 Structural concrete 2000 Bearings 2100 Open foundations 2600 Expansion joints 2700 Wearing coat and appurtenances

The

maintenance operations involved the assessment of road condition, diagnosis of the problem and adopting the most appropriate maintenance step.

General causes of pavement failure1. 2. 3. 4. 5. 6.

Defects in the quality of material use. Defect in construction method. Defect in quality control during construction. Settlement of foundation of embankment it self. Increase in the magnitude of the wheel loads. Environment factors including heavy rainfall, soil erosion, high water table, snow fall etc.

Typical Flexible Pavement FailureReflection Cracking

Joint reflection cracking on an arterial.

Longitudinal Cracking

Longitudinal cracking from poor longitudinal joint construction

Potholes

Pothole on a road after heavy rains

Slippage (Shrinkage) Cracking

Water Bleeding

Typical Rigid Pavement FailureBlowup

Corner Break

Linear Cracking

Types of Maintenance:I. II. III.

Routine maintenance Periodic maintenance Special repairs(rehabilitation)

Routine maintenanceRoutine maintenance include following I. Upkeep of carriage way. II. Maintenance of shoulders and sub grade. III. Maintenance of side drains and other ancillary works. IV. Patch repairs of pot holes and localized failures.

Periodic maintenanceI. II. III. IV. V. VI. VII. VIII. IX.

Line Painting Crack Sealing Asphalt Patching Re-shouldering Slopes Bridge and Pavement Inspections Minor Bridge Maintenance Signs, Barriers & Guide rails Re-lamping

Special maintenanceI. II. III. IV.

Asphaltic Overlays Surface Treatments Major Bridge/Structure Maintenance Sign Replacement

Maintenance of bituminous surface

Patch repairs:- patch repairs are carried out on the damaged orimproper road surface.

bituminous binders and premix material is placed in the section.

Pot holes repair:-the excavated patches are clean and painted with Surface treatment:-it is customary to spread blotting materials such Resurfacing:- if the surface is totally worn out and develop a poor riding

as aggregate chips or maximum size of about 10 mm or course send during summer.

surface it may be more economical to provide an additional surface course on the existing surface.

Maintenance of Cement concrete surface I.

Main defects in this types of surface is formation of cracks. Maintenance of joint is also require in this surface. Cracks develop in rigid surface classified as under Temperature cracks:- the cracks are filled by suitable gradebituminous sealing compound, heated to liquid consistency.

II.

slabs.

Structure cracks:- in this type of crack we have to recast the failure

Crack Sealing Operations

Routing Traffic control

Sealing Cleaning & Drying

HIGHWAY SAFETY

For safety and operational reasons it will be necessary to provide suitable safety features and other facilities along the project road. These features will includeSafety barriers Road markings Route markers Road delineators Parking areas & rest areas road signs Road lighting Kilometre stones ROW pillars Weighbridges

SAFETY FEATURES

does not slip . The Safety Barrier shall conform to NHAI/MoRTH Circulars. Safety barriers shall be located at sharp horizontal curves, high embankments and at bridge approaches.

Safety Barriers